Fuel valves with safety latching means



Nov. 4, 1969 c. s. J. KINGMA FUEL VALVES WITH SAFETY LATCHING MEANSFiled Jan. 24, 1966 Fig.

INVENTOR. CORNELIS S. J. KINGMA ATTORNEY United States Patent 3,476,130FUEL VALVES WITH SAFETY LATCHING MEANS Cornelis S. .I. Kingma, Emmen,Netherlands, assignor to Honeywell G.m.b.H., Frankfurt-Main, Germany, acorporation of Germany Filed Jan. 24, 1966, Ser. No. 522,615 (llaimspriority, application Germany, Mar. 27, 1965, H 55,613; May 15, 1965, H56,042 Int. Cl. FZSd /16; F16k 51/00; F23q 9/08 US. Cl. 137-66 5 2Claims ABSTRACT OF THE DISCLOSURE A fuel valve including a rotatableplug valve and a thermocouple operated safety valve in series flowrelationship and having a latch cooperating with the plug valve so thatwhen the plug valve is returned from an on position to a positionbetween the on and off positions but wherein the fuel flow may beinsufficient to support combustion at a burner controlled by the valveand thereby cause the flame at such burner to be extinguished, it cannotagain be turned toward the on position until the safety valve closes andthereby disables the latch.

This invention relates to fuel valves and more specifically to thosefuel valves having a manually operable control valve and a safety valvewhich must be manually opened and then is held open by a flameresponsive device so long as a flame exists at a burner to which theflow of fuel is controlled by the valve. Specifically, the inventionrelates to valves as described above wherein there is provided means forrestricting the movement of the manual valve when the safety valve isopen.

In controlling the flow of fuel, such as gas, to burners for furnacesand appliances, it is customary to utilize a valve having a manualcontrol valve and a safety valve which will automatically shut off theflow of fuel should the flame be extinguished. Various types of manualvalves and safety valves have been devised in the past and are wellknown in the art. The safety valves utilize various types of operatorssuch as bimetals, expansible rods and the like, but the most popular isthe type utilizing a thermoelectric generator heated by the flame andenergizing an electromagnet which is not strong enough to open thesafety valve but of suflicient strength to hold it open when it ismanually opened. In all of these types of flame-sensing operators forsafety valves there is a certain amount of heat inertia so that thesafety valve does not close immediately upon the flame beingextinguished. Due to this phenomena, it has been possible for adangerous condition to be inadvertently created by establishing a flameand manually setting the safety valve, and then moving the manual valveto a position so that the flame is extinguished but reopening it beforethe flame-responsive operator for the safety valve has cooledsufficiently to close the safety valve. When this occurred, gas wasallowed to flow to the burner without the presence-of a flame and, insome instances, suflicient gas accumulated at the burner to create ahazardous condition without the operator being aware of what hadhappened.

The possibility of such a condition being inadvertently brought abouthas been recognized in the past. For example, the Putz et al. Patent3,099,994 discloses an arrangement wherein a control including a manualga valve and a thermocouple safety valve is provided with a latchingarrangement which precludes movement of the manual valve from its closedposition unless the safety valve is closed. The structure disclosed inthe Putz et al. patent is utilized in connection with a manual valve ofthe type wherein a rotatable operator operates an axially movabledisc-type valve. There appears to be no readily apparent "ice way ofadapting the structure of Putz et al. to the more conventional rotatableplug or disc-type manual gas valve. In addition, the structure disclosedin Putz et al. is very complex, including a plurality of co-actingparts, several of which have odd shapes which would require ratherdelicate machining operations rendering the structure expensive toproduce.

My invention is deemed to be an improvement over the disclosure of Putzet al. It provides a simple and easily manufactured latching arrangementwhich can be readily incorporated into most conventional fuel valveswithout substantial redesign of the valves or substantial retooling fortheir production. This latching arrangement precludes the manual valvefrom being reopened until the safety valve has been closed, should themanual valve be moved to a flame-extinguishing position after a flamehas been established. The invention is particularly applicable to fuelvalves utilizing a rotatable plug or disc-type valve with a rotatablemanual operator but may be utilized in axially movable valves of thegeneral type disclosed in Putz et al. so long as there is a rotatableportion of the valve and manual operator combination. A latching surfaceis provided which is rotatable with the previously mentioned rotatableportion of the manual valve-operator combination and extends generallyparallel to the axis of rotation of this portion. The latching surfaceis disposed so that it traverses an arcuate path when the manual valvemeans is moved. A cooperating latching member is mounted for movementtoward and away from the path of the latching surface, transverse to theaxis of rotation thereof. A resilient means is provided for urging thelatching member into the path of the latching surface and the latchingmember is operably connected to the safety valve and is moved therebyout of the path of the latching surface when the safety valve is closed.

Various objects and advantages of my invention will become apparent uponreading the following detailed description of certain preferredembodiments thereof wherein reference is made to the drawing.

In the drawing: FIGURE 1 is an elevational view, partially in crosssection, disclosing a fuel valve utilizing my invention; FIGURE 2 is afragmentary plan view disclosing the manual operator for the valve;FIGURE 3 is a fragmentary cross-sectional view taken generally alongline 3-3 of FIGURE 1; FIGURE 3a is a fragmentary cross-sectional Viewgenerally similar to FIGURE 3 but disclosing a slightly modified form ofthe invention; FIG- URE 4 is an enlarged view of a latching member whichforms part of the invention; FIGURE 5 is a top view of the latchingmember of FIGURE 4; FIGURE 6 is a front view of the latching member ofFIGURES 4 and 5; FIG- URE 7 is an enlarged fragmentary view of a portionof the structure disclosed in FIGURE 3; FIGURE 8 is an enlargedfragmentary view of a portion of the structure disclosed in FIGURE 3a;and FIGURE 9 is a schematic representation of a programming arrangementfor the manual valve.

Referring to FIGURE 1, reference numeral 10 generally designates a fuelcontrol valve for controlling the flow of a fuel, such as gas, to aburner. Valve 10 includes a body or housing 11 which may take the formof a generally cup-shaped casting having an inlet 12. Preferably valveIt) has a main outlet (not shown) which is adapted to be connected to amain burner 13 and a pilot outlet (not shown) which is adapted to beconnected to a pilot burner 14. Valve 10 includes a manualvalve-operator combination 15 and a safety valve 16 which are connectedin series relationship to control the flow of gas through the valve. Theparticular form of the manual valve-operator combination is not criticalbut the manual valve must be movable between at least an on and an offposition and, during movement between these positions, at least aportion of the valve-operator combination must rotate. Preferably themanual valve is a rotatable plug or disc but the invention may also beused in connection with axially movable disc-type valves if desired. Theparticular configuration of the safety valve is also not critical to theinvention and, while various types of flame-responsive safety valves maybe used, the conventional thermocouple type safety valve is preferred. Ihave chosen to disclose, by Way of example, a rotatable plug valve andthermocouple safety valve generally similar to that discolsed in theWalter F. Allingham Patent Number 3,236,252 assigned to the assignee ofthe present invention. Since the particular structure of the manualvalve and operator and the safety valve are not critical, these deviceswill be described only briefly herein.

Valve body 11 may be cast with a tapered valve seat 17 for a rotatableplug valve 20 which has operably connected thereto a manual operatortaking the form of a knob 21 disposed above the upper surface of body11. Plug valve 20 has a central opening extending upwardly into it fromthe lower end thereof and connecting to a transverse port (not shown)which is adapted to connect into a passage in the valve body when thevalve is rotated to a particular angular position. I have chosen todisclose the plug valve as being rotatable from an off position topilot, high and low positions, as seen in FIGURE 3. The angular positionof the plug valve may be indicated by providing a fixed mark 22 on thevalve body to cooperate with appropriate indicia on knob 21. It is to beunderstood that it is not essential to the invention that this pluralityof positions be provided for the plug valve, it being essential onlythat the valve have off and on positions. The term on position, as usedherein, is intended to include a pilot position, One or more main burneron positions, or both.

Safety valve 16 includes a valve closure member 23 which is adapted tocooperate with the lower end of plug valve 20 to control the flow offuel therethrough. Closure member 23 is operably connected to a stem 24which extends up through the center of the plug valve and is connectedto knob 21. A spring 25 urges closure member 23 downward away from theend of the plug valve and into engagement with one end of a lever 26which is pivoted on a downwardly extending portion 27 of valve body 11,as by a pin 30. The other end of lever 26 is engaged by a plate 31 whichis connected to the armature (not shown) of an electromagnetic unit 32including a coil which is adapted to be energized by a thermocouple 33disposed to be heated by a pilot burner 14. A spring 34 urges plate 31downwardly and rotates lever 26 in a counter clockwise direction toclose closure member 23 when the electromagnet in unit 32 isde-energized. When the magnet is energized, it has insufficient strengthto draw the armature upward but can hold the armature upward against theforce of spring 34 when the device is reset as by depressing knob 21.When the magnet in unit 32 is energized and holds plate 31 up, spring 25holds closure member 23 away from the end of plug valve 20.

As indicated, the structure described thus far is old and forms no partof my invention. My invention lies in combining with the structuredescribed above, a simple latching arrangement to preclude moving themanual valve from a substantially closed position to an open positionwhen the safety valve is open. This is accomplished by providing on arotatable portion of the manual valveoperator combination, a latchingsurface which cooperates with a latching member 41. Latching surface 40may be formed on any rotatable portion of the manual valve-operatorcombination, and in the case of the plug valve and knob disclosedherein, may be either on the plug valve or the knob. However, I havechosen to form it on a peripheral wall of plug valve 20 near the bottomof the plug valve. Latching surface 40 may take the form of anindentation or depression such as shown in FIG- URES 1 and 3 or it maytake the form of a generally 4 radially extending cam-like protrusion40a as disclosed in FIGURE 3a.

Latching member 41 is a bell-crank type member having a generallycylindrical portion 41a which is rotatably mounted on pin 30. Extendingfrom cylindrical portion 41a are a pair of spaced, parallel, finger-likemembers 41b which are adapted to engage the upper portion of lever 26adjacent the point where it engages closure member 23 and to straddle aneck portion 23a of member 23. Extending from cylindrical portion 41a,generally per pendicular to fingers 41b, is an arm 41c which has atransverse latching portion 41d extending in the direction of fingers41b and generally parallel thereto. It will be obvious that as the plugvalve is rotated the latching surface 40 will traverse an arcuate pathand the latching member is so constructed and disposed that portion 41dthereof is rotatable into and out of this path. Latching member 41 isresiliently urged in a clockwise direction by an appropriate biasingmeans such as a spring 42 which may be a generally U shaped elementencircling cylindrical portion 41a and having one end abutting a fixedabutment 43 on housing 11 and the other end bent so as to have a portion42a disposed in a slot 41e formed in arm 41c of the latching member. Ifdesired, a groove 41 may be formed in cylindrical portion 41a to aid inpositioning spring 42. Latching member 41 is constructed so thatwhenever the safety valve is open, spring 42 urges latching portion 41dinto engagement with the peripheral wall of plug valve 20 so that whenthe plug valve is rotated to a position wherein latching surface 40 isadjacent to the latching member, portion 41d will drop into thedepression or be intersected by the cam-like protrusion if thearrangement of FIGURE 3a is utilized.

While it is desirable to preclude turning the valve to an on positionwhen the flame has been extinguished and the safety valve is open, it isessential that the manual valve be rotatable from an on to an offposition regardless of the position of the safety valve. This isfacilitated by forming the latching surface 40 with an abutment portion40a which engages latching portion 41d of the latching member when theplug valve is rotated in a counter-clockwise direction (as seen inFIGURE 2) and with a sloping surface 40b which engages portion 41d ofthe latching member when the plug valve is rotated in a clockwisedirection. Sloping surface 40b does not preclude rotation of the plugvalve but simply cams the latching member in a counter-clockwisedirection, in opposition to spring 42, and allows the plug valve torotate with respect to it. If the cam-like protrusion (disclosed inFIGURE 3a) is utilized, a similar provision can be made by providing anabutting surface 140a which abuts substantially flatly against thelatching member when the plug valve is rotated in a counter-clockwisedirection and a sloping cam surface 14012 which simply urges thelatching member outwardly away from the plug valve when the valve isrotated in a clockwise direction.

The location of the latching surface 40 may be such that the,plug valveis latched, and thereby prevented from being rotated towards on, onlywhen the valve is turned all the way to the off position. However,generaly a flame at the pilot burner will be extinguished before thevalve is turned all the way to the off position. Therefore, it may bedesirable to locate latching surface 40 at a point intermediate the offand pilot positions. By way of example, the latching surface has beenlocated in the illustrative embodiment so that the valve is latched at aposition about 60 from the off position. Thus, any time that the valveis in a pilot or on position and a flame exists at burners 14 and/ or13, and the plug valve is then rotated backwards a distance sufficientlybeyond the pilot position, toward the off position, so that the flamemight be extinguished at pilot burner 14, the latch becomes effective topreclude turning the valve back toward the on position until the safetyvalve has dropped out.

In valves of the type described herein, it is customary to provide aprogramming arrangement so that the valve can be operated only through asafe lighting sequence. This is generally provided by a programmingtrack or groove, in either a portion of the valve body or in the knob,and a cooperating pin in the other one of the two members. By way ofexample, one such programming arrangement is disclosed in FIGURE 9 wherea pin 50, which is attached to knob 21, operates in a programming groove51 which is a portion of the body. This structure is conventional and isnot disclosed in FIGURE 1 and it will be understood that the disclosureof FiGURE 9 is schematic and for purposes of explanation only. In aconventional programming arrangement, it may be possible to depress knob21 to open the safety valve any time when the plug valve is in the offor pilot position. It will be understood that knob 21 is biased upwardby a means not shown in this disclosure. Thus, in the off position, pin50 occupies the position shown in dashed lines and indicated at 50a inFIGURE 9. To rotate to the pilot position, the knob must be depressedsufficiently to move the pin under a downwardly extending portion of thearea surrounding programming slot 51. Thus, the programming slot wouldfollow the dashed portion shown in FIGURE 9. The knob could be depressedto move pin 50 to a position 50b and then rotated to a position 50c tosupply gas to the pilot burner which could then be ignited. The safetyvalve would be held open until the thermocouple provides suflicientcurrent to energize the electromagnet in unit 32 to hold the safetyvalve. At this time the knob can be released to allow the pin to moveupward to a position 50d where it may be rotated to positions 50c and 50for high or low operation of the main valve as desired. However, withthe latching structure provided by my invention, the Valve cannot berotated toward the on position if the safety valve is open. Thus, inorder to get the plug valve to the pilot position, it is necessary tomodify the programming slot so that knob 21 cannot be depressed untilthe plug valve has been rotated past the position where the latchingsurface and the latching member coact. This position is indicated by thesolid line position of pin 50 in FIGURE 9.

The operation of the structure will be apparent from the foregoingdescription. When it is desired to ignite burner 14, knob 21 isdepressed slightly and rotated to the pilot position wherein it isdepressed to position 50c and a flame established at the pilot burner.When the thermocouple unit has energized the magnet in unit 32, thesafety valve remains open and the plug valve may be rotated to either ofthe on positions. It is possible to turn the plug valve back to thepilot position, extinguishing the main burner but maintaining a flame atthe pilot burner, without bringing the latching apparatus intooperation. However, should the plug valve be rotated backwards beyondthe pilot position, toward the off position sufliciently so that theflame might be extinguished at pilot burner 14, it brings latchingsurface 40 into cooperative engagement with latching member 41, and thecooperation of the latching surface and latching member will precluderotation of the plug valve toward the pilot and on positions, so long asthe safety valve is open. However, the plug valve can be rotated back tothe off position. Once the safety valve has closed, lever 26 pivotslatching member 41 to a position wherein latching surface 41b is out ofthe path of latching surface 40. The valve can then be operated again inthe manner described above.

I claim:

1. A fuel valve having manual valve means including a closuremember-manual operator combination movable between off and on positionsand including a portion which is rotated during such movement, theclosure member being constructed so that it progressively closes a fuelpassage as the manual valve means is moved from the on toward the offposition, a safety valve which must be manually opened and which is thenheld open in the presence of flame by a flame responsive device, andlatch means operable to restrict movement of the manual valve means whenthe safety valve is held open by the flame responsive device,characterized by: a latching surface extending generally parallel to theaxis of rotation of said rotatable portion and rotatable with therotatable portion of said manual valve means, said latching; surfacetraversing an arcuate path upon movement of the manual valve means; acooperating latching member movable transversely to the axis of rotationof said rotatable portion; means mounting laid latching member formovement into and out of the path of said latching surface; meansresiliently urging said latching member into the path of said latchingsurface; said latching surface and said latching member being disposedso that they engage when the closure member is in a predeterminedposition between said off and on positions and wherein the closuremember has closed the fuel passage to the extent that it may allowinsufficient fuel flow therethrough to support combustion at a burnercontrolled by the valve; and means operably associated with saidlatching member and said safety valve for moving said latching memberout of the path of said latching surface when said safety valve isclosed.

2. The fuel valve of claim 1 wherein the manual valve closure member isa rotatable plug valve, and wherein said latching surface comprises arecess in the peripheral surface of the plug and disposed so that alatching portion of said latching member extends thereinto only whensaid plug is in said predetermined angular position, between said offand said on positions, and said safety valve is open.

References Cited UNITED STATES PATENTS 3,099,994 8/1963 Putz et al.13766 3,236,252 2/1966 Allingham l3766 3,303,866 2/1967 Ray 431-54WILLIAM F. ODEA, Primary Examiner R. GERARD, Assistant Examiner US. Cl.X.R. 25 l287; 43 l54

